Echolocation visualisation (echosonar)
If this is the look you are aiming for, unless you need to export this somewhere else, you could achieve it just by using generated coordinates.

Simply use world coordinates for your texture. Start with Object coordinates, then run them through a Vector Transform node from Object to World.



Alternatively, I imagine your bat emitting sound waves will be moving, so instead use an external object as source for texture coordinates, like an empty, then animate its position or parent it to the bat.



In both cases just animate the Color Ramp's position parameter for the stops to achieve the "moving rings" effect.